Rewrote the implementation of the SwapEndian_16() and SwapEndian_32() functions so that they compile down in most instances to minimal loads and stores rather than complicated shifts.

Fixed SCSI.c implementations of all the demos/projects casting the block count to a 32-bit temporary before calling SwapEndian_16().

3 files changed, 17 insertions, 25 deletions

diff --git a/Demos/Device/ClassDriver/MassStorage/Lib/SCSI.c b/Demos/Device/ClassDriver/MassStorage/Lib/SCSI.c
index 6c20576c8..08b055fbe 100644
--- a/Demos/Device/ClassDriver/MassStorage/Lib/SCSI.c
+++ b/Demos/Device/ClassDriver/MassStorage/Lib/SCSI.c
@@ -160,7 +160,7 @@ static void SCSI_Command_Inquiry(USB_ClassInfo_MS_Device_t* MSInterfaceInfo)
 	uint8_t PadBytes[AllocationLength - BytesTransferred];
 	
 	/* Pad out remaining bytes with 0x00 */
-	Endpoint_Write_Stream_LE(&PadBytes, (AllocationLength - BytesTransferred), NO_STREAM_CALLBACK);
+	Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), NO_STREAM_CALLBACK);
 
 	/* Finalize the stream transfer to send the last packet */
 	Endpoint_ClearIN();
@@ -257,7 +257,7 @@ static void SCSI_Command_ReadWrite_10(USB_ClassInfo_MS_Device_t* MSInterfaceInfo
 	BlockAddress = SwapEndian_32(*(uint32_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[2]);
 
 	/* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
-	TotalBlocks  = SwapEndian_16(*(uint32_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[7]);
+	TotalBlocks  = SwapEndian_16(*(uint16_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[7]);
 	
 	/* Check if the block address is outside the maximum allowable value for the LUN */
 	if (BlockAddress >= LUN_MEDIA_BLOCKS)
diff --git a/Demos/Device/ClassDriver/MassStorageKeyboard/Lib/SCSI.c b/Demos/Device/ClassDriver/MassStorageKeyboard/Lib/SCSI.c
index 2b4477aad..897090c91 100644
--- a/Demos/Device/ClassDriver/MassStorageKeyboard/Lib/SCSI.c
+++ b/Demos/Device/ClassDriver/MassStorageKeyboard/Lib/SCSI.c
@@ -170,7 +170,7 @@ static bool SCSI_Command_Inquiry(USB_ClassInfo_MS_Device_t* MSInterfaceInfo)
 	uint8_t PadBytes[AllocationLength - BytesTransferred];
 	
 	/* Pad out remaining bytes with 0x00 */
-	Endpoint_Write_Stream_LE(&PadBytes, (AllocationLength - BytesTransferred), NO_STREAM_CALLBACK);
+	Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), NO_STREAM_CALLBACK);
 
 	/* Finalize the stream transfer to send the last packet */
 	Endpoint_ClearIN();
@@ -196,7 +196,7 @@ static bool SCSI_Command_Request_Sense(USB_ClassInfo_MS_Device_t* MSInterfaceInf
 	uint8_t PadBytes[AllocationLength - BytesTransferred];
 
 	Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, NO_STREAM_CALLBACK);
-	Endpoint_Write_Stream_LE(&PadBytes, (AllocationLength - BytesTransferred), NO_STREAM_CALLBACK);
+	Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), NO_STREAM_CALLBACK);
 	Endpoint_ClearIN();
 
 	/* Succeed the command and update the bytes transferred counter */
@@ -306,15 +306,11 @@ static bool SCSI_Command_ReadWrite_10(USB_ClassInfo_MS_Device_t* MSInterfaceInfo
 	uint32_t BlockAddress;
 	uint16_t TotalBlocks;
 	
-	/* Load in the 32-bit block address (SCSI uses big-endian, so have to do it byte-by-byte) */
-	((uint8_t*)&BlockAddress)[3] = MSInterfaceInfo->State.CommandBlock.SCSICommandData[2];
-	((uint8_t*)&BlockAddress)[2] = MSInterfaceInfo->State.CommandBlock.SCSICommandData[3];
-	((uint8_t*)&BlockAddress)[1] = MSInterfaceInfo->State.CommandBlock.SCSICommandData[4];
-	((uint8_t*)&BlockAddress)[0] = MSInterfaceInfo->State.CommandBlock.SCSICommandData[5];
-
-	/* Load in the 16-bit total blocks (SCSI uses big-endian, so have to do it byte-by-byte) */
-	((uint8_t*)&TotalBlocks)[1]  = MSInterfaceInfo->State.CommandBlock.SCSICommandData[7];
-	((uint8_t*)&TotalBlocks)[0]  = MSInterfaceInfo->State.CommandBlock.SCSICommandData[8];
+	/* Load in the 32-bit block address (SCSI uses big-endian, so have to reverse the byte order) */
+	BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
+
+	/* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
+	TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
 	
 	/* Check if the block address is outside the maximum allowable value for the LUN */
 	if (BlockAddress >= LUN_MEDIA_BLOCKS)
diff --git a/Demos/Device/LowLevel/MassStorage/Lib/SCSI.c b/Demos/Device/LowLevel/MassStorage/Lib/SCSI.c
index 10e6bc4a7..111c3b726 100644
--- a/Demos/Device/LowLevel/MassStorage/Lib/SCSI.c
+++ b/Demos/Device/LowLevel/MassStorage/Lib/SCSI.c
@@ -159,7 +159,7 @@ static void SCSI_Command_Inquiry(void)
 	uint8_t PadBytes[AllocationLength - BytesTransferred];
 	
 	/* Pad out remaining bytes with 0x00 */
-	Endpoint_Write_Stream_LE(&PadBytes, (AllocationLength - BytesTransferred), StreamCallback_AbortOnMassStoreReset);
+	Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 
 	/* Finalize the stream transfer to send the last packet */
 	Endpoint_ClearIN();
@@ -182,7 +182,7 @@ static void SCSI_Command_Request_Sense(void)
 	uint8_t PadBytes[AllocationLength - BytesTransferred];
 	
 	/* Pad out remaining bytes with 0x00 */
-	Endpoint_Write_Stream_LE(&PadBytes, (AllocationLength - BytesTransferred), StreamCallback_AbortOnMassStoreReset);
+	Endpoint_Write_Stream_LE(&PadBytes, sizeof(PadBytes), StreamCallback_AbortOnMassStoreReset);
 
 	/* Finalize the stream transfer to send the last packet */
 	Endpoint_ClearIN();
@@ -256,16 +256,12 @@ static void SCSI_Command_ReadWrite_10(const bool IsDataRead)
 	uint32_t BlockAddress;
 	uint16_t TotalBlocks;
 	
-	/* Load in the 32-bit block address (SCSI uses big-endian, so have to do it byte-by-byte) */
-	((uint8_t*)&BlockAddress)[3] = CommandBlock.SCSICommandData[2];
-	((uint8_t*)&BlockAddress)[2] = CommandBlock.SCSICommandData[3];
-	((uint8_t*)&BlockAddress)[1] = CommandBlock.SCSICommandData[4];
-	((uint8_t*)&BlockAddress)[0] = CommandBlock.SCSICommandData[5];
-
-	/* Load in the 16-bit total blocks (SCSI uses big-endian, so have to do it byte-by-byte) */
-	((uint8_t*)&TotalBlocks)[1]  = CommandBlock.SCSICommandData[7];
-	((uint8_t*)&TotalBlocks)[0]  = CommandBlock.SCSICommandData[8];
-	
+	/* Load in the 32-bit block address (SCSI uses big-endian, so have to reverse the byte order) */
+	BlockAddress = SwapEndian_32(*(uint32_t*)&CommandBlock.SCSICommandData[2]);
+
+	/* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
+	TotalBlocks  = SwapEndian_16(*(uint16_t*)&CommandBlock.SCSICommandData[7]);
+
 	/* Check if the block address is outside the maximum allowable value for the LUN */
 	if (BlockAddress >= LUN_MEDIA_BLOCKS)
 	{